The present invention relates to a liquid flow-out prevention valve or liquid shutoff valve, which is, for example attached to a fuel tank of a vehicle. The valve operates to prevent increase of a pressure in the fuel tank by releasing a fuel vapor in the tank to atmosphere, and to prevent fuel from flowing outside the fuel tank when the vehicle is accelerated, decelerated or turned quickly.
As a conventional liquid flow-out prevention valve, there is a valve having a relief valve with an inlet disposed parallel to an outlet of a cut-off valve formed at an upper part of the cut-off valve, the inlet being connected to a flow path communicating with the outlet, such as disclosed in Japanese Utility Model Publications (KOKOKU) No. 6-6983 and No. 6-6984.
In the liquid flow-out prevention valve disclosed in Japanese Publication No. 6-6983, since the relief valve is formed above the cut-off valve, the height or size of the valve becomes large.
Also, since the inlet of the relief valve orients and opens downwardly, when a vehicle is accelerated, decelerated or turned quickly, fuel flowing into the liquid flow-out prevention valve ascends to provide a large force. This large force opens or lifts up a valve body closing the inlet of the relief valve by a coil spring to open the inlet of the relief valve. Accordingly, fuel in the fuel tank may flow into the flow path.
In the liquid flow-out prevention valve disclosed in Japanese Publication No. 6-6984, a relief valve is disposed beside a cut-off valve to shorten the height or size. However, similar to the valve disclosed in Publication No. 6-6983, since the inlet of the relief valve orients and opens downwardly, when a vehicle is accelerated, decelerated or turned quickly, fuel in the fuel tank may flow into the flow path from the inlet of the relief valve.
The present invention has been made to obviate the above drawbacks, and an object of the invention is to provide a liquid flow-out prevention valve, wherein the height and size of the valve can be reduced.
Another object of the invention is to provide a liquid flow-out prevention valve as stated above, wherein a liquid does not flow into a flow path.
A further object of the invention is to provide a liquid flow-out prevention valve as stated above, wherein an inlet of a relief valve is not clogged by foreign materials.
Further objects and advantages of the invention will be apparent from the following description of the invention.